RE: Ethereal timings vs ping timings

Hi,

Don't forget that the ARP protocol is probably running before the
first ICMP packet is sent out.

Thanx,
Jaap

On Wed, 14 Jun 2006, Visser, Martin wrote:

> I have seen this problem with the Windows ping in the past. The first
> ping always gives a very high response time compared to subsequent ones.
>
> ping MMM.NNN.50.1
> PING MMM.NNN.50.1 (16.145.50.1): 56 data bytes
> 64 bytes from MMM.NNN.50.1: icmp_seq=0 ttl=255 time=73 ms
> 64 bytes from MMM.NNN.50.1: icmp_seq=1 ttl=255 time=0 ms
> 64 bytes from MMM.NNN.50.1: icmp_seq=2 ttl=255 time=1 ms
> 64 bytes from MMM.NNN.50.1: icmp_seq=3 ttl=255 time=1 ms
> 64 bytes from MMM.NNN.50.1: icmp_seq=4 ttl=255 time=0 ms
>
> ----MMM.NNN.50.1 PING Statistics----
> 5 packets transmitted, 5 packets received, 0.0% packet loss
> round-trip (ms)  min/avg/max/med = 0/15/73/1
>
> I believe that is an internal Windows issue (something to do with the
> delay of loading the ICMP.dll) and not related to actual time-of-flight
> of the ICMP echo.
>
> When I have used windows ping in doing doing network analysis from
> scripts I either disregard the first response (or use another ping
> program!)
>
>
> Martin Visser
>
> Technology Consultant
> Consulting & Integration
> Technology Solutions Group - HP Services
>
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> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Anis BEN
> ABDALLAH
> Sent: Monday, 12 June 2006 8:20 PM
> To: [email protected]
> Subject: [Ethereal-dev] Ethereal timings vs ping timings
>
> Hello,
>
> I'm testing an embedded ethernet device and when trying with the ping
> command, I have a different timings between reply timings indicated by
> the ping command in the dos window and timings indicated in the ethereal
> (time delta from previous packet)
>
> For example for the first reply I got "time = 9ms" in dos window while
> in ethereal I have "time delta from previous packet = 0.00055 s"
>
> Why this difference?
>
> Thanks for your help.
>
> Anis
>
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